Stopwatch external app (#2553)

firmware/application/external/stopwatch/ui_stopwatch.cpp

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2025 Mark Thompson
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "ui_stopwatch.hpp"
+#include "portapack.hpp"
+#include "ch.h"
+
+using namespace portapack;
+
+namespace ui::external_app::stopwatch {
+
+StopwatchView::StopwatchView(NavigationView& nav) {
+    add_children({
+        &labels,
+        &button_run_stop,
+        &button_reset_lap,
+        &button_done,
+        &big_display,
+        &lap_display,
+    });
+
+    button_run_stop.on_select = [this](Button&) {
+        if (running)
+            stop();
+        else
+            run();
+    };
+
+    button_reset_lap.on_select = [this](Button&) {
+        if (running)
+            lap();
+        else
+            reset();
+    };
+
+    button_done.on_select = [&nav](Button&) {
+        nav.pop();
+    };
+}
+
+void StopwatchView::focus() {
+    button_run_stop.focus();
+}
+
+void StopwatchView::run() {
+    running = true;
+    start_time = chTimeNow() - previously_elapsed;
+    button_run_stop.set_text("STOP");
+    button_reset_lap.set_text("LAP");
+}
+
+void StopwatchView::stop() {
+    running = false;
+    end_time = chTimeNow();
+    previously_elapsed = end_time - start_time;
+    button_run_stop.set_text("START");
+    button_reset_lap.set_text("RESET");
+}
+
+void StopwatchView::reset() {
+    lap_time = end_time = start_time = previously_elapsed = 0;
+    big_display.set(0);
+    lap_display.set(0);
+}
+
+void StopwatchView::lap() {
+    lap_time = chTimeNow();
+    lap_display.set((lap_time - start_time) * 1000);  // convert elapsed time in ms to MHz for BigFrequency widget
+}
+
+void StopwatchView::paint(Painter& painter) {
+    (void)painter;
+    if (running) {
+        end_time = chTimeNow();
+        big_display.set((end_time - start_time) * 1000);  // convert elapsed time in ms to MHz for BigFrequency widget
+    }
+}
+
+void StopwatchView::frame_sync() {
+    set_dirty();
+}
+
+}  // namespace ui::external_app::stopwatch